Currently, so called uhle boxes are used in the paper making process to condition press felts. These boxes are in fact vacuum pipes with slots of different size and shape directed towards the inside. The air flows through felt, which is moving over slots, and is then sucked off to a vacuum pump. During the process water and other contaminants from felt are sucked away together with air. This is a crucial stage for appropriate paper dewatering in the press section. Current paper machines are running at a speed much higher than the speed of air flowing through felt. The cross-directional movement of a fast moving felt versus airflow leads to a deflection of the air stream in the direction of running felt and therefore causes considerable reduction in the working surface of uhle box.
In case of very fast paper machines this leads to a total cancellation of the open airflow surface and consequently hinders any felt conditioning.
The presented method improves the currently employed technologies in order to enhance paper production process.